I have purchased a couple HB that had serial number 001 for this was the first kit the builder built. If it was me, I would use the serial number the kit manufacturer uses. One of these examples was a Rans. Now years later when I look back at paper work for these airplanes, I can not go by serial numbers for more then one had the same serial number. I must go by manufacturer or N number if it had an N number.

Tony